1. Filed of the Invention
The present invention relates to a card connector, and more particularly to a low profile card connector capable of reliably holding an inserted card.
2. Description of the Prior Art
In electronic devices such as cellular phones, telephones, Personal Digital Assistants (PDA) and digital cameras, a variety of functions are added by inserting an IC (integrated circuit) card with a built-in CPU or memory IC, such as a SIM (subscriber identity module) card, an MMC (multimedia card), an SD (secure digital) card, an MS (Memory Stick) and an SM (Smart Media) card.
Card connectors are provided for connecting such cards to circuit boards of the electronic devices. U.S. Patent Application Publication No. 2001/0055897 A1 discloses a card connector for selectively accommodating a first card defining a retention notch and a second card without a retention notch. The conventional card connector comprises a case retaining a plurality of terminals for electrically connecting with contact pads of the first or the second card. In one embodiment as disclosed in FIGS. 25-27 of the ""897 A1 publication, the case is made of insulative material and has an elongate raised portion 88. The card connector has a slider for removing an inserted card. The slider has a card retaining arm 85 guided by the raised portion 88 for retaining the inserted card and thereby preventing the inserted card from falling out of the connector.
When the first card having a retention notch is inserted into the card connector, the raised portion 88 guides the card retaining arm 85 along an inner side thereof and prevents the card retaining arm 85 from moving outwardly, thereby securely retaining the inserted first card. When the second card without a retention notch is inserted into the card connector, the card retaining arm 85 is displaced outwardly to move along an outer side of the raised portion 88. Therefore, the raised portion 88 functions as a guide means for guiding the movement of the card retaining arm 85.
However, in order to restrict the outward movement of the card retaining arm 85, the raised portion 88 has a relatively high height. The profile of the case is increased because of the provision of the raised portion 88. As a result, the case having a high profile occupies relatively large space of an electrical device. Furthermore, since a large amount of friction force is exerted on the raised portion 88 made of insulative material, the insulative raised portion 88 tends to be abraded after a long term of use, resulting in an improper guidance of the card retaining arm 85 and an unreliable retaining of the inserted card.
To solve the above-mentioned problem, in another embodiment of the conventional card connector, the raised portion 88 is replaced by an elongate groove defined in the case. When the first card is inserted, the card retaining arm 85 moves into the elongate groove and is prevented from outwardly moving. When the second card is inserted, the card retaining arm 85 slides on a step-down portion of the case. However, the card retaining arm 85 moves along different planes when the first or the second card is inserted into the card connector, resulting in a fluctuating movement of the retaining arm 85. After a long period of use, the card retaining arm 85 tends to separate from the slider, resulting in an unreliable retaining of the inserted first or the second card. Furthermore, the provision of the elongate groove in the case weakens the intensity of the case, resulting in a short life-span thereof.
It is well known that a card has a chamfered corner for preventing an erroneous insertion thereof into a card connector. However, the conventional card connector cannot prevent an erroneous card insertion until a large portion of the card has been inserted into the connector. Such an erroneous engagement between the large portion of the card and the connector still may cause harm to both the card and the connector.
Hence, an improved card connector is desired to overcome the above-mentioned shortcomings.
A main object of the present invention is to provide a low profile card connector capable of reliably holding an inserted card in a compact manner.
Another object of the present invention is to provide a card connector which is robust and durable.
A further object of the present invention is to provide a card connector capable of preventing an erroneous insertion of a card thereinto at an early stage of insertion of the card.
A card connector in accordance with the present invention is provided to accept a card having a notch in its side edge. The card connector comprises an insulative housing, a plurality of contacts retained in the housing, an eject mechanism mounted on the housing, an elastic locking piece and a metal shell. The insulative housing defines a card receiving space for receiving the card. The eject mechanism comprises an eject member for moving in a card insertion/ejection direction in response to the card insertion/ejection operation. The elastic locking piece is attached to the eject member and is moved as the eject member moves in the card insertion or ejection direction. The elastic locking piece comprises a locking portion for engaging with the notch of the card, a stationary portion fixed in the eject member, and a protruding portion projecting from the locking portion. The metal shell substantially covers the housing and defines a guide hole. The guide hole is provided to accommodating and guiding the protruding portion of the elastic locking piece.
When the elastic locking piece is biased by the card before the locking portion engages with the notch during an earlier card insertion operation, the protruding portion is displaced in a first direction. When the locking portion engages with the notch during a later card insertion operation, the protruding portion moves in a second direction opposite to the first direction.
The guide hole is defined in the metal shell without increasing the profile of the card connector and without affecting the intensity of the housing. Therefore, the card connector of the present invention has a low profile and a relatively long life-span, and is also capable of reliably holding the inserted card.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.